package demo;

public class Computer {
    public void powerOn(){
        System.out.println("打开电脑");
    }
    public void powerOff(){
        System.out.println("关闭电脑");
    }

    public void useDevice(USB usb){
        usb.openDevice();
        if(usb instanceof Mouse){
            Mouse mouse=(Mouse)usb;
            mouse.click();
        }else if ( usb instanceof KeyBoard ){
            KeyBoard keyboard=(KeyBoard)usb;
            keyboard.input();
        }

    }
}
